Repositionable closure device

ABSTRACT

A closure device includes a first ring structure having a first distal portion and a first medial portion and a second ring structure having a second distal portion and a second medial portion. The first and second distal portions are movable between an open position, where the first and second distal portions form an angle relative to one another for receiving target tissue therebetween, and a closed position, where the first and second distal portions are drawn toward one another for gripping the target tissue. The device also includes an anvil about which the first and second medial portions are formed. Either one of proximal motion of the anvil relative to the first and second rings or proximal motion of the medial portions relative to the anvil causes the first and second distal portions to move into either one of the open position or the closed position.

PRIORITY CLAIM

The present disclosure claims priority to U.S. Provisional PatentApplication Ser. No. 63/198,155 filed Sep. 30, 2020; the disclosure ofwhich is incorporated herewith by reference.

FIELD

The present disclosure relates to an endoscopic closure deviceactuatable between an open position and a closed position multiple timesso that the device may be repositioned on target tissue.

BACKGROUND

Many endoscopic devices with distal clipping mechanisms, e.g. hemostasisclips, have a single-use quick launch mechanism. Once the clip has beenclosed, it is not possible to re-open and reposition the clip. If theclip is not deployed at the correct position on the target tissue thereis no opportunity to reposition the clip. Additionally, many currentclosure devices are insufficient for certain perforations, conditionsand anatomies and may be difficult to use or time-consuming in certainsituations.

SUMMARY

The present disclosure relates to a closure device which includes afirst ring structure having a first distal portion and a first medialportion and a second ring structure having a second distal portion and asecond medial portion. The first and second distal portions are movablebetween an open position, where the first and second distal portionsform an angle relative to one another for receiving target tissuetherebetween, and a closed position, where the first and second distalportions are drawn toward one another for gripping the target tissue.The device also includes an anvil about which the first and secondmedial portions are formed. Either one of proximal motion of the anvilrelative to the first and second rings or proximal motion of the medialportions relative to the anvil causes the first and second distalportions to move into either one of the open position or the closedposition.

In an embodiment, the device further includes a locking mechanism forlocking the first ring and the second ring in the closed position, theanvil including a first mechanical feature sized, shaped and positionedto engage a second mechanical feature on at least one of the first ringand the second ring when the first and second rings are in the closedposition.

In an embodiment, the first mechanical feature is a locking window andthe second mechanical feature is a locking tab extending from the firstmedial portion.

In an embodiment, the first mechanical feature is a locking window andthe second mechanical feature is a locking tab extending from the secondmedial portion.

In an embodiment, a distal end of the first distal portion extendsdistally beyond a distal end of the second distal portion.

In an embodiment, the device further includes a first gripping featureextending from one of the first distal portion and the second distalportion toward the other one of the first and second distal portions.

In an embodiment, one of the first and second medial portions includes aprotrusion configured to engage an end of the anvil to maintain theanvil at a desired position between the first and second medialportions.

In an embodiment, the first and second rings are biased toward theclosed position.

In an embodiment, the first and second rings are biased toward the openposition.

In an embodiment, the device further includes flexible connecting strutsadjacent to the anvil and extending between the first medial portion ofthe first ring and the second medial portion of the second ring; firstrecesses adjacent to a first proximal portion of the first ring; andsecond recesses adjacent to a second proximal portion of the secondring. The first and second recesses are sized and shaped to receive theanvil therebetween.

In an embodiment, the first and second rings have a curvature at each ofthe first and second medial portions sized and shaped to receive theanvil therebetween.

The present disclosure also relates to a system which includes a closuredevice comprising a first ring structure having a first distal portionand a first medial portion, a second ring structure having a seconddistal portion and a second medial portion, the first and second distalportions being movable between an open position, where the first andsecond distal portions form an angle relative to one another forreceiving target tissue therebetween, and a closed position, where thefirst and second distal portions are drawn toward one another forgripping the target tissue, and an anvil about which the first andsecond medial portions are formed, wherein either one of proximal motionof the anvil relative to the first and second rings or proximal motionof the medial portions relative to the anvil causes the first and seconddistal portions to move into either one of the open position or theclosed position; a flexible control member coupled to one of the anviland the first and second rings to move the closure device between theopen and closed position; and a cap configured to be attached to adistal end of an endoscope, the cap including a recess within which theclosure device is seated.

In an embodiment, the closure device has a stem attached to a firstproximal portion of the first ring and a second proximal portion of thesecond ring, the control member extending through the stem, the stembeing sized and shaped to be received within a working channel of theendoscope, the member having a failure point proximal to the stem and aloop at a distal end thereof extending around the anvil such thatproximal movement of the member moves the anvil proximally.

In an embodiment, the system further includes a grasper having a pair ofgrasping jaws configured to move the first and second distal portionsbetween the open and the closed positions and a shaft extending from aproximal end of the pair of grasping jaws through the working channel ofthe endoscope.

In an embodiment, the anvil has a length greater than a diameter of thecap.

Furthermore, the present disclosure relates to a method for graspingtissue which includes mounting a closure device on a cap; attaching thecap to a distal end of an endoscope, the closure device comprising afirst ring structure having a first distal portion and a first medialportion, a second ring structure having a second distal portion and asecond medial portion, the first and second distal portions beingmovable between an open position, where the first and second distalportions form an angle relative to one another for receiving targettissue therebetween, and a closed position, where the first and seconddistal portions are drawn toward one another for gripping the targettissue, and an anvil about which the first and second medial portionsare formed; moving proximally one of the anvil and the first and secondrings relative to the other one of the anvil and the first and secondrings to move the first and second distal portions between the openposition or the closed position.

In an embodiment, the method further includes locking the anvil relativeto the first and second rings to lock the first and second rings in theclosed position.

In an embodiment, the closure device has a stem attached to a firstproximal portion of the first ring and a second proximal portion of thesecond ring, a control member extending through the stem, the stem beingsized and shaped to be received within a working channel of theendoscope, the member having a failure point proximal to the stem and aloop at a distal end thereof extending around the anvil.

In an embodiment, drawing the member proximally moves the anvilproximally relative to the first and second rings and drawing the memberfurther proximally increases tension on the member until the failurepoint fails and the closure device separates from the cap and theendoscope.

In an embodiment, a grasper having a pair of grasping jaws and a shaftextending from a proximal end of the pair of grasping jaws through aworking channel of the endoscope moves the first and second distalportions between the open and closed positions.

BRIEF DESCRIPTION

FIG. 1 shows a closure device according to a first exemplary embodimentbiased in a naturally closed position.

FIG. 2 shows the closure device of FIG. 1 actuated into an openposition.

FIG. 3 shows the closure device of FIG. 1 with a secondary device foractuating the closure device.

FIG. 4 shows the closure device of FIG. 1 actuated into the openposition with the secondary device of FIG. 3 .

FIG. 5 shows a closure device according to a second exemplary embodimentbiased in a naturally open position.

FIG. 6 shows the closure device of FIG. 5 actuated into a closedposition.

FIG. 7 shows a closure device mounted to a cap and coupled to anendoscopic shaft.

FIG. 8 shows a closure device according to a third exemplary embodimentbiased in a naturally open position and having features for lockingclosed.

FIG. 9 shows a side view of the closure device of FIG. 8 in an openposition.

FIG. 10 shows a side view of the closure device of FIG. 8 in a closedposition.

FIG. 11 shows an embodiment of the closure device of FIG. 5 including alocking mechanism.

DETAILED DESCRIPTION

The present disclosure may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present disclosurerelates to devices for closing, e.g. clipping target tissue. Asdescribed herein, the term “clip” or “clipping device” refers to devicesconfigured to lock into a closed position around target tissue during aninterventional procedure, e.g. to stanch blood flow, and which are leftin the body after actuation. Certain of the exemplary embodiments mayalso relate to devices for gripping, e.g. “clamping” tissue duringinterventional procedures, e.g. to approximate tissue for suturing by afurther device, which are not locked into a closed position and may beopened and removed from the body before the procedure is completed.Devices operable for either one or both of clipping/clamping may bereferred to as “closure devices.”

Each of the devices has two rings actuatable between an open positionand a closed position relative to one another. In some embodiments, therings are initially biased toward the closed position and actuating thedevice spreads the rings, while in other embodiments the rings areinitially biased toward the open position and actuating the device drawsthe rings together. Each of the devices described herein has anactuation mechanism that may operate the opening/closing multiple times,i.e., that is operable to both open and close as many times as deemednecessary by the operating physician to correct a position at which theclosure force is applied. Some of the embodiments described herein, e.g.for clipping devices, are configured so that the rings may be lockedtogether in the closed position when the operating physician determinesthat the placement of the clip is correct.

Certain of the embodiments described herein have components that aremountable within a distal end of a working channel of an endoscope tohold the apparatus in a desired position against a distal end of anendoscope, while others are mountable to an exterior of the distal endof the endoscope, and still others are extended distally beyond aworking channel of the endoscope and have a connection therein withoutdirect mounting to the endoscope. An actuator, i.e. a user interface forthe actuation mechanism, at the handle of the endoscope generallyprovides an actuation tension via pull wire to operate the closuredevice.

In some embodiments, when the device is mounted to the endoscope, theendoscope may provide a load bearing surface to resist a proximallydirected force due to the tension applied to the pull wire so that theactuation load operates to move the rings into a desired oppositeposition (open or closed) relative to one another from an initialposition toward which they are biased (i.e., a position to which therings revert when no actuating force is applied to the pull wire). Aswill be described below, the endoscope-mounted embodiments are generallydirectly actuated by a pull wire, while the unmounted embodiments areactuated by a grasper or similar device.

As will be described in further detail below, each of the embodimentshas a closure aspect comprising two rings. The two rings are joined viaa connecting linkage that may vary between embodiments. For example,some embodiments comprise proximal portions of the rings that are weldedor otherwise joined together, while other embodiments are connected bymedial struts. A medial portion of each of the rings is disposed aroundor adjacent to an anvil, e.g. a wedge, a rod, a pin, a divider, etc.that acts as a pivot point about which the rings deform or rotate. Eachof the devices is actuated in one of a plurality of ways.

In some embodiments, the anvil may be translated, e.g. drawn proximally,by a pull wire causing the medial portions of the rings to elasticallydeform about the anvil forcing the rings into a position (i.e. open orclosed) different than the initial position. In other embodiments, aportion of one or both of the rings positioned proximal to the anvil istranslated, e.g. drawn proximally, by a pull wire, elastically deformingmedial portions of the rings around a stationary anvil and forcing therings into a different position. In still other embodiments, a grasperor similar device translates a proximal portion of one or both of therings relative to the anvil which acts as a pivot point forcing a distalportion of one or both of the rings into a different position.

FIGS. 1-2 shows a closure device 100 according to a first exemplaryembodiment comprising a first ring 110 and a second ring 120 with medialportions 116, 126 formed about an anvil 102 so that gripping distalportions 112, 122 of the rings 110, 120 are biased toward a naturallyclosed position. In the present embodiment, each of the grippingportions 112, 122 has an open center hole. One or both of the grippingportions 112, 122 (in this embodiment, both) comprises teeth 114, 124extending from an inner surface of the corresponding gripping portiontoward the other of the gripping portions 112, 122 so that target tissuemay be gripped therebetween. However, in other embodiments, the grippingends 112, 122 may have no teeth, or may comprise plates instead ofcenter holes, to be described further below.

In the present embodiment, the gripping portions 112, 122 of the firstand second rings 110, 120 are substantially flat and parallel to oneanother while in the naturally biased closed position, as seen in FIG. 1. The gripping portions 112, 122 are semi-circular, however other shapesmay be used. The gripping portions 112, 122 may be offset by a givendistance, depending on the size of the target tissue to be gripped. Inother words, a distal end 113 of the gripping portion 112 extendsdistally beyond a distal end 123 of the gripping portion 122.

In this embodiment, the gripping portion 112 of the first ring 110 isshown to extend further distally than the gripping portion 122 of thesecond ring 120. However, in other embodiments, the rings 110, 120 maysubstantially mirror one another, i.e. have a same longitudinalextension, or be offset from one another differently than shown in thepresent embodiment. In embodiments where the rings 110, 120 have teeth114, 124, the rings 110, 120 should be arranged so that the teeth 114,124 are offset from one another, i.e. not interfere with one another,when the rings 110, 120 are in the closed position.

The first ring 110 defines a pair of medial portions 116 adjacent to theanvil 102 that cooperate with a corresponding pair of medial portions126 of the second ring 120 to form a detent within which the anvil 102resides when in the closed position. That is, the medial portions 116,126 of the rings 110, 120 define a space sized and shaped to receive theanvil 102 therein so that, when the anvil 102 resides in this space, therings 110, 120 are substantially parallel to one another in a desiredposition so that the teeth 114 and 124 will grip tissue trappedtherebetween.

The medial portions 116 of the first ring 110 are formed with acurvature that extends around and partially matches a curvature of theanvil 102 (in this embodiment the anvil 102 is at least partiallycylindrical). The medial portions 126 of the second ring 120 are alsoshaped to receive the anvil 102 and may be symmetric with or differentlyshaped from the medial portions 116 of the first ring 110. In thisembodiment, the medial portions 126 are separated from the anvil 102 agiven distance, then curve and extend toward the first ring 110 atpositions proximal to the anvil 102. In addition, each of the medialportions 126 includes a slider bar 125 engaging an end of the anvil 102to maintain the anvil 102 centered between the first and second rings110, 120. Those skilled in the art will understand that the slider bars125 may be placed on either of the first and second rings 110. 120 asdesired.

Proximal to the medial portions 116, 126 are the proximal portions 118,128 of the rings 110, 120, which are tightly spaced until meeting at aproximal-most point. The proximal portions 118, 128 are held together inany desired manner. For example, the proximal portions 118, 128 may becoupled to one another by being crimped or welded to one another orotherwise joined at this proximal position or by being coupled to thestem 104 in any known manner. Although a particular shape for each ofthe rings 110, 120 has been described, other curvatures and spacings forthe medial portions 116, 126 and proximal portions 118, 128 may be usedwithout departing from the scope of the disclosure.

The anvil 102 in this embodiment is a partially cylindrical rod having adiameter greater than the spacing between the proximal portions 118, 128of the rings 110, 120 when the rings 110, 120 are closed. The anvil 102may be joined to the rings 110, 120 in various ways so that the anvil102 remains situated between the rings 110, 120 but may move proximallyand distally relative thereto. In other words, the anvil 102 may bejoined to the rings 110, 120 so that it does not slide out from betweenthe rings 110, 120. For example, the anvil 102 may be shaped in a way toprevent sliding, i.e. may have a shape that is not uniformlycylindrical. The anvil 102 may change diameter so that the diameter isreduced at the location where the rings 110, 120 cross the anvil 102,effectively preventing the larger diameter remainder of the anvil 102from sliding past the rings 110, 120.

The rings 110, 120 are shaped so that drawing the anvil 102 proximallyrelative to the rings 110, 120 brings the anvil 102 into contact withthe tightly spaced proximal portions 118, 128 forcing the rings 110, 120to separate, as seen in FIG. 2 , and bring the closure device 100 intothe open position. In the present embodiment, the distal portions 112,122 of the rings 110, 120 preferably open to an angle α (between thefirst and second rings 110, 120) of between 45 and 180 degrees, or morespecifically, between 75 and 100. Those skilled in the art willunderstand that the angle α is chosen to ensure that, in the openposition, the distal ends 113, 123 of the first and second rings 110,120, respectively, are separated from one another by a gap sufficient toreceive a desired portion of target tissue therebetween for grippingand, although this angle may vary between the various embodiments thesame angular ranges apply to all of the disclosed embodiments. In someembodiments, only one of the two rings 110, 120 may open relative to theother of the two rings 110, 120, while in other embodiments, both of therings 110, 120 may open away from one another.

The point at which the rings 110, 120 are joined, e.g. the weld, has astem 104 joined thereto through which a pull wire 106 is extended. Thepull wire 106 has a loop 108 extending around the anvil 102 so thatproximal motion of the pull wire 104 draws the anvil 102 proximallytherewith. The stem 104 may be snugly received in the working channel ofan endoscope or within a channel running outside the scope or otherwisestably held in a desired position on the distal end of the endoscope aswould be understood by those skilled in the art. When an actuation forceis applied to the device 100, the endoscope against which the device 100is held provides a resistive force to offset the actuation load. Forexample, the pull wire 106 may extend proximally through the endoscope(e.g., through a working channel of the endoscope) to exit the handle ofthe endoscope via a port, or may be connected to a feature on the handleallowing the pull wire 106 to be easily pulled proximally to applytension or to be locked in a desired location to maintain a desiredstate of the device.

For example, the feature on the handle may comprise a reel to take upthe slack of the pull wire 106, a lever, a rotary knob, a plunger, etc.As tension is applied to the pull wire 106, the device is drawnproximally against the endoscope increasing tension on the pull wire 106and drawing the anvil 102 proximally between the rings 110, 120 to movethe device to the open position. As long as tension is maintained on thepull wire 106, the anvil 102 is held between the proximal portions 118,128 keeping the device in the open position. The tension may be appliedmanually, or there may be a locking feature at the handle formaintaining the pull wire at a desired tension.

When tension is released from the pull wire 106 (e.g., when the devicehas been positioned with desired tissue to be gripped between the rings110, 120), the natural bias of the rings 110, 120 draws the rings 110,120 together forcing the anvil 102 back into the space between themedial portions 116, 126 returning the device to the closed positiongripping the desired tissue. A manual lock may engage when the anvil 102is allowed to move to a fully closed position so that, when the clip islocked over desired tissue, proximal tension may be applied to the pullwire 106 until a predetermined failure point 107 (e.g., a weakenedportion of the pull wire 106) is severed releasing the clip from thepull wire 106. For example, tabs on the one or both rings 110, 120 mayengage a proximal side of the anvil 102 when the anvil 102 moves to adistal-most position corresponding to the fully closed configuration.

Because the device 100 is naturally biased in the closed position, whenthe rings 110, 120 are positioned at a desired location on the targettissue, the pull wire 106 may be severed and the device 100 will remainon the target tissue until it sloughs off of the target tissue at alater time. The devices described that have a naturally closed bias donot need a further mechanism for locking the device 100 closed, whereasthose devices described later that have a naturally open bias, and areintended to remain in a closed position on target tissue after thedevice is positioned thereon, have a further mechanism for locking thedevice closed.

In alternate embodiments, rather than having a stem 104 facilitating theuse of a pull wire 106 joined to proximal portions of the rings 110,120, the closure device 100 may utilize a secondary tool to actuate therings 110, 120. For example, as shown in FIGS. 3-4 , a grasper 150 maybe used to pull the anvil 102 from a distal position in which the rings110, 120 are closed, to a proximal position in which anvil forces therings 110, 120 apart against their natural bias to the open tissuereceiving configuration. As would be understood by those skilled in theart, the rings 110, 120 of this embodiment and the anvil 102 are formedsubstantially similarly to the rings 110, 120 and the anvil 102 of theembodiment of FIG. 1 .

As would be understood by those skilled in the art, many types ofgrasper or grasping tool may be used. The exemplary grasper 150 hasfirst and second grasping halves 152, 154, respectively. In one methodof use, the first grasping half 152 may be positioned against a distalfacing portion of the anvil 102 while the second grasping half 154 ispositioned against a proximal edge of the proximal portions 118, 128 ofthe rings 110, 120 so that as the grasper 150 is closed (i.e., thegrasping halves 152, 154 are drawn together), the anvil 102 is drawnproximally between the proximal portions 118, 128 forcing the device 100into the open position. When the grasping halves 152, 154 are allowed toseparate from one another, the rings 110, 120 will be drawn together bytheir natural bias forcing the anvil 102 distally into the space betweenthe medial portions 116, 126 returning the device to the closedposition.

FIG. 3 shows the grasper 150 in an open position with the closure device100 gripped within the first and second grasping halves 152, 154 but notyet actuated, while FIG. 4 shows the grasper 150 in a closed positionwith the first and second grasping halves 152, 154 drawn together andthe anvil 102 forced from the distal position to the proximal positionbetween the rings 110, 120, forcing the gripping ends of the rings 110,120 apart from one another into the open position. Although a grasper150 is described, other secondary devices operable to grip the device100 and bring the anvil 102 proximally relative to the rings 110, 120may be used. When the secondary device is used, the closure device 100need not be coupled directly to the endoscope. The secondary device maybe extended through the working channel of the endoscope and mayinternally provide the actuation force and resistive force needed toopen the closure device 100 as with known graspers while the closuredevice 100 need only be held in place so that, as a force is appliedthereto via the secondary device, the anvil 102 may be moved relative tothe rings 110, 120.

The present configuration allows the closure device 100 to secure targettissue between the gripping portions 112, 122, to approximate and/orcompress the target tissue to e.g. stem blood flow through an opening inthe target tissue, bring the tissue together for suturing, or toapproximate or compress tissue for any other reason. The open ringconfiguration allows tissue adjacent to the portion gripped by thegripping portions 112, 122 to expand between the center holes of thegripping portions 112, 122 of the rings 110, 120 when the grippingportions 112, 122 are closed onto the target tissue.

In another embodiment, the gripping portions 112, 122 comprise platesinstead of having open center holes. This configuration compresses alltissue between the plates and forces tissue adjacent to this compressedtissue to move outward from edges of the plates via an open side of thering configuration. This arrangement permits tissue forced out of theplates to then be treated (e.g., resected via a secondary tool) as wouldbe understood by those skilled in the art.

FIGS. 5-6 shows a closure device 200 according to a second exemplaryembodiment comprising a first ring 210 and a second ring 220 havingmedial portions 216, 226 with an anvil 202 received therebetween so thatthe gripping distal portions 212, 222 of the rings 210, 220 may be movedbetween an open position and a closed position. In this embodiment, therings 210, 220 are biased toward a naturally open position, as shown inFIG. 5 . In the present embodiment, the gripping portions 212, 222 haveopen center holes and do not include teeth. However, in otherembodiments (as shown in FIG. 11 ), the gripping portions 212, 222 mayinclude inward-facing teeth 214, 224 similar to those teeth 114, 124described above with regard to closure device 100, or may compriseplates instead of center holes, as described above.

In the present embodiment, the first and second rings 210, 220 areformed to create a natural bias so that the gripping portions 212, 222,when not acted on by an outside force, move to an open position in whichthey are angled relative to one another so that the distal ends of therings 210, 220 are spaced apart from one another. As indicated above,the range of an angle between the first and second rings 210, 220 ispreferably selected to be sufficiently large to permit a target portionof tissue to be gripped to be received between the distal ends of therings 210, 220.

Those skilled in the art will understand that tissue may be drawnbetween the gripping elements of any of the embodiments described hereinusing any known methods or devices (e.g., suction, graspers, etc.). Eachof the gripping portions 212, 222 extends substantially straight (alonga curved path within a single plane) with these planes angled relativeto one another and intersecting adjacent to the medial portions 216, 226each of which curves out of the plane of the distal portion of itscorresponding gripping portion 212, 222 around opposite sides of theanvil 202 which is received between the gripping portions 212, 222.

In this embodiment, because the planes in which the gripping portions212, 222 intersect is distal to the medial portions 216, 226, the medialportion 216 passes on a side of the anvil 202 opposite a side on whichthe distal end of the corresponding gripping portion 212 extends andsimilarly for the medial portion 226 and its corresponding grippingportion 222. That is, as can be seen in FIG. 5 , the gripping portion212 of the first ring 210 extends above the anvil 102 while the medialportion 216 passes below the anvil 202. Similarly, the gripping portion222 of the first ring 210 extends below the anvil 202 while the medialportion 226 passes above the anvil 202. The medial portions 216, 226curve around the anvil 202 with a partial curvature selected, in thisembodiment, to substantially match a curvature of a portion the anvil202 which will be in contact with the corresponding medial portion in amanner similar to that described for the medial portions 116, 126 of theclosure device 100 relative to the anvil 102. The proximal portions 218,228 of the rings 210, 220 are tightly spaced until meeting at aproximal-most point at which the rings 210, 220 are connected, e.g.,welded, in a manner similar to the closure device 100.

Unlike the closure device 100, the closure device 200 is actuated bydrawing the proximal portions 218, 228 of the rings 210, 220 proximally,rather than by drawing the anvil 202 proximally. As may be seen moreclearly in FIG. 6 , drawing the proximal portions 218, 228 of the rings210, 220 proximally causes the gripping portions 212, 222 to angulateuntil they are brought nearly parallel to one another—i.e., until distalends of the gripping portions 212, 222 approach one another in a closedposition. The curvature of the medial portions 216, 226 is such thatwhen the proximal portions 218, 228 are drawn proximally, inner surfacesof the medial portions 216, 226 on the distal side of the anvil 202facing the anvil 202 are brought into contact with the anvil 202. Thiscontact, in combination with the proximal force, acts to angulate themedial portions 216, 226 which in turn brings the distal portions 212,222 toward one another.

Similarly to the closure device 100, the closure device 200 may comprisea stem for mating the closure device 200 to the working channel of anendoscope. A secondary device may also be used to actuate the closuredevice 200, however, the secondary device must be operable to spread theanvil and the proximal portions 218, 228 apart from one another, ratherthan pushing them closer together.

The device 200 may include a locking mechanism for locking the rings210, 220 in the closed position. As shown in FIG. 11 , the anvil 202includes at least one mechanical feature that is sized and shaped toengage a corresponding mechanical feature on at least one of the rings210, 220. In the exemplary embodiment, the anvil 202 includes a firstlocking window 232 at a first end and a second locking window 234 at asecond end. The first locking window 232 is configured to engage a frontlocking tab 236 extending from the medial portion 226 and the secondlocking window 234 is configured to engage a rear locking tab 238extending from the medial portion 226.

When the rings 210, 220 are positioned in a location corresponding to alocking position, the locking tabs 236, 238 align with the lockingwindows 232, 234, therefore locking the rings 210, 220 relative to theanvil 202. In other words, when the proximal portions 218, 228 are drawnproximally a predetermined distance, the locking tabs 236, 238 slideinto the locking windows 232, 234 to lock the rings 210, 220 in theclosed position. When in the closed position, the angle between thefirst and second rings 210, 220 is preferably selected to be less than20 degrees. Although the locking mechanism is described above relativeto the closure device 200, one skilled in the arts will understand thatthe locking mechanism may be used with all the exemplary embodiments. Asthose skilled in the arts will understand, embodiments of the closuredevice where the anvil is moved proximally relative to the rings (e.g.,the closure device 100), the locking mechanism has mechanical featureson the anvil positioned to align with corresponding mechanical featureson the rings to lock the closure device in the closed position.

In another embodiment, the closure system 300 includes a clipping device301 mounted on a cap 302 configured to be mounted over the distal end ofan endoscope 304 or other insertion instrument. FIG. 7 shows theclipping device 301 mounted on the cap 302 with an anvil 306 thereofreceived in diametrically opposed recesses 308 of the cap 302. The cap302 is sized and shaped so that it may slid over the distal end of anendoscope 304 while remaining out of the way of the optics and workingchannel of the endoscope 304 as would be understood by those skilled inthe art. A pull wire 310 extending through the working channel of theendoscope 304 is coupled to the proximal portions of the rings of thedevice 301 and includes a failure point 312 as described above. Theanvil 306 is positioned between first and second rings 314, 316 of thedevice 301 so that, as the pull wire 310 is pulled proximally, the firstand second rings 314, 316 are drawn proximally over the anvil 306 (whichis held in position by the cap 302) drawing the first and second rings314, 316 toward each other into the closed position to grip tissuereceived therebetween.

As with prior embodiments, when the first and second rings 314, 316 havebeen drawn to the fully closed configuration, drawing the pull wire 310further proximally (e.g., via an actuator on a proximal handle thatremains outside the body accessible to a user) increases tension on thepull wire 310. During this proximal retraction of the pull wire 310, theanvil 306 is locked mechanically in the closed position (e.g., by tabson one or both of the rings 314, 316 which, once positioned distally ofthe anvil 306 prevent the anvil 306 from moving distally therepast).Once, the device 301 has been mechanically locked in the closedposition, drawing the pull wire 310 further proximally increases thetension on the pull wire 310 until the failure point 312 failsseparating the device 301 from the pull wire and permitting theendoscope 304 including the cap 302 to be withdrawn from the body whileleaving the device 301 within the body clipped over target tissue.

The device 300 shown in FIG. 7 has an anvil 306 with a length greaterthan a diameter of the cap 302 (or of the portion of the cap 302traversed by the anvil 306 when it is received in the recesses 308) sothat the anvil 306 can be securely seated in the recesses 308. However,the anvil 306 may have a length substantially equal to the separationbetween the recesses 308 so that the ends of the anvil 306 do notprotrude beyond the outer profile of the cap 302.

FIGS. 8-10 show a closure device 400 according to a third exemplaryembodiment comprising a first ring 410 and a second ring 420 joined bytwo flexible connecting struts 404 configured to establish an anglebetween the rings 410, 420 based on a position of an anvil 402 proximalto the struts 404. Unlike the previously described embodiments, therings 410, 420 of the closure device 400 are not formed with a curvatureextending around an initial position of the anvil 402. Rather, each ofthe rings 410, 420 is substantially planar, with the exception ofproximal recesses 419, 429 to be explained further below.

The rings 410, 420 of the closure device 400 may be substantiallysymmetrical with the exception of a placement of teeth 414, 424 on thedistal ends of the distal portions 412, 422, which may have an offsetrelative to the teeth of the opposing ring so as to not interfere withone another when the device 400 is in the closed position. However,substantial symmetry is not required. The connecting struts 404 arelocated at and form a bridge between positions 416, 426 on the rings410, 420, the positions 416, 426 being proximal to a centerline of therings 410, 420. The distal portions 412, 422 of the rings 410, 420distal to the positions 416, 426 may be used for gripping target tissue.

The device 400 is shaped so that the rings 410, 420 are naturallysplayed in an open position. That is, the rings 410, 420 are biased toassume an open position in which distal ends thereof are separated fromone another and force must be applied to move the device 400 to theclosed position in which the distal ends of the rings 410, 420 are drawninto proximity to one another to grip tissue therebetween. Thus, theproximal portions 418, 428 of the rings 410, 420 proximal to thepositions 416, 426 where the connecting struts 404 are located arenaturally angled toward one another. The anvil 402, when the rings 410,420 are in the open position, is located adjacent to the connectingstruts 404.

In a manner similar to the device 100 described above, the anvil 402 maybe drawn proximally relative to the rings 410, 420 by means of a pullwire (not shown) or via a separate device. Drawing the anvil 402proximally brings the anvil 402 into contact with progressively moreproximal portions of the inner surfaces of the proximal portions 418,428 of the rings 410, 420 and spreads the proximal portions 418, 428apart from one another, which in turn closes the distal portions 412,422 as each of the rings 410, 420 rotates substantially about an axisdefined by the points at which the connecting struts 404 couple to thecorresponding ring 410, 420.

The proximal portions 418, 428 include recesses 419, 429 shaped toreceive the anvil 402 therebetween so that, when the anvil 402 has beendrawn proximally relative to the rings 410, 420, sufficient to bring therings 410, 420 to the closed position, the anvil 402 snaps into therecesses 419, 429 and the device 400 is locked in the closed position asthe bias of the rings 410, 420 secures the anvil 402 in the recesses419, 429. In operation, the device 400 may have three configurationstates: open, closed, and locked. Prior to locking the device 400, theoperating physician may bring the device 400 between the open positionand closed position multiple times. When the physician has confirmedthat a currently closed positioning of the device 400 on target tissueis correct, the anvil 402 may be drawn further distally to lock thedevice 400 closed by snapping the anvil 402 into the recesses 419, 429.

It will be appreciated by those skilled in the art that changes may bemade to the embodiments described above without departing from theinventive concept thereof. It should further be appreciated thatstructural features and methods associated with one of the embodimentscan be incorporated into other embodiments. It is understood, therefore,that this invention is not limited to the particular embodimentdisclosed, but rather modifications are also covered within the scope ofthe present invention as defined by the appended claims.

The invention claimed is:
 1. A closure device, comprising: a first ringstructure having a first distal portion and a first medial portion; asecond ring structure having a second distal portion and a second medialportion, the first and second distal portions being movable between anopen position, where the first and second distal portions form an anglerelative to one another for receiving target tissue therebetween, and aclosed position, where the first and second distal portions are drawntoward one another for gripping the target tissue; and an anvil aboutwhich the first and second medial portions are formed, wherein eitherone of proximal motion of the anvil relative to the first and secondrings or proximal motion of the medial portions relative to the anvilcauses the first and second distal portions to move into either one ofthe open position or the closed position.
 2. The device of claim 1,further comprising: a locking mechanism for locking the first ring andthe second ring in the closed position, the anvil including a firstmechanical feature sized, shaped and positioned to engage a secondmechanical feature on at least one of the first ring and the second ringwhen the first and second rings are in the closed position.
 3. Thedevice of claim 2, wherein the first mechanical feature is a lockingwindow and the second mechanical feature is a locking tab extending fromthe first medial portion.
 4. The device of claim 2, wherein the firstmechanical feature is a locking window and the second mechanical featureis a locking tab extending from the second medial portion.
 5. The deviceof claim 1, wherein a distal end of the first distal portion extendsdistally beyond a distal end of the second distal portion.
 6. The deviceof claim 1, further comprising: a first gripping feature extending fromone of the first distal portion and the second distal portion toward theother one of the first and second distal portions.
 7. The device ofclaim 1, wherein one of the first and second medial portions includes aprotrusion configured to engage an end of the anvil to maintain theanvil at a desired position between the first and second medialportions.
 8. The device of claim 1, wherein the first and second ringsare biased toward the closed position.
 9. The device of claim 1, whereinthe first and second rings are biased toward the open position.
 10. Thedevice of claim 1, further comprising: flexible connecting strutsadjacent to the anvil and extending between the first medial portion ofthe first ring and the second medial portion of the second ring; firstrecesses adjacent to a first proximal portion of the first ring; andsecond recesses adjacent to a second proximal portion of the secondring, wherein, the first and second recesses are sized and shaped toreceive the anvil therebetween.
 11. The device of claim 1, wherein thefirst and second rings have a curvature at each of the first and secondmedial portions sized and shaped to receive the anvil therebetween. 12.A system, comprising: a closure device comprising a first ring structurehaving a first distal portion and a first medial portion, a second ringstructure having a second distal portion and a second medial portion,the first and second distal portions being movable between an openposition, where the first and second distal portions form an anglerelative to one another for receiving target tissue therebetween, and aclosed position, where the first and second distal portions are drawntoward one another for gripping the target tissue, and an anvil aboutwhich the first and second medial portions are formed, wherein eitherone of proximal motion of the anvil relative to the first and secondrings or proximal motion of the medial portions relative to the anvilcauses the first and second distal portions to move into either one ofthe open position or the closed position; a flexible control membercoupled to one of the anvil and the first and second rings to move theclosure device between the open and closed position; and a capconfigured to be attached to a distal end of an endoscope, the capincluding a recess within which the closure device is seated.
 13. Thesystem of claim 12, wherein the closure device has a stem attached to afirst proximal portion of the first ring and a second proximal portionof the second ring, the control member extending through the stem, thestem being sized and shaped to be received within a working channel ofthe endoscope, the member having a failure point proximal to the stemand a loop at a distal end thereof extending around the anvil such thatproximal movement of the member moves the anvil proximally.
 14. Thesystem of claim 12, further comprising: a grasper having a pair ofgrasping jaws configured to move the first and second distal portionsbetween the open and the closed positions and a shaft extending from aproximal end of the pair of grasping jaws through a working channel ofthe endoscope.
 15. The system of claim 12, wherein the anvil has alength greater than a diameter of the cap.